Endoscopic surgery has seen rapid growth over the past decade. By way of background, a conventional endoscope generally is an instrument with a light source and image sensor for visualizing the interior of an internal region of a body. A wide range of applications have been developed for the general field of endoscopes including by way of example the following: arthroscope, angioscope, bronchoscope, choledochoscope, colonoscope, cytoscope, duodenoscope, enteroscope, esophagogastro-duodenoscope (gastroscope), laparoscope, laryngoscope, nasopharyngo-neproscope, sigmoidoscope, thoracoscope, and utererscope (individually and collectively, “endoscope”). In order to form an image of the scene under observation, a light source and image sensor are features that may be provided at or near the distal end portion of an insertion section of the endoscope that is to be inserted into the body, where the term “distal end portion” includes a distal end face—as well as a side of the distal section of—the insert portion of the endoscope. Endoscopes may also incorporate additional functionality for observation or operation within the body, such as a working channel for passing diagnostic, monitoring, treatment, or surgical tools through the endoscope, where the working channel has an opening located at the distal end portion of the insert.
The advantages of minimally invasive surgery performed with the help of an endoscope are well known and understood in the medical field. As a result, there have been a growing number of devices for use with endoscopes for delivering, for example, diagnostic, monitoring, treatment, operating instruments, tools, and accessories (collectively, “tools”) into the observation field and working space of the physician's endoscope.
Some of the endoscopic devices on the market are short and stiff while others are long and flexible. In either case, the devices normally utilize tubes from which the tools may extend or exit. These tubes are typically coupled to the endoscope at or near the distal end portion of the endoscope insertion section (the “insert”) by an attachment tip that does not articulate.
Rather, the attachment tip as known and presently used in the market of endoscope accessories is merely formed from an integral piece of plastic with a lumen. Thus, the attachment tip is affixed to the endoscope in an immovable manner, e.g., elastic band or with medical grade tape having an adhesive layer or other means such as glue to hold the attachment tip and distal end portion of the endoscope insertion section together.
The lumen of the attachment tip is typically co-axial with, parallel with, or at a fixed angle relative to, the distal end portion of the insert. This is also true in the case of an endoscope that has a working channel at the distal end portion of the insert, whereby the attachment tip lumen is co-axial, parallel, or angularly fixed with respect to the distal opening of the working channel. Regardless of whether the insert has a working channel or not, the attachment tip is constrained to the side of the endoscope insertion section and does not move independently thereof. Thus, for a flexible endoscope, when the distal end portion of the insert is flexed or bent, then the attachment tip will move in accordance with the movement of the distal end portion. Conversely, when the distal end portion of the insert remains stationary, the attachment tip likewise remains stationary. Otherwise stated, there is no independent moveable part in the conventional attachment tip that permits articulation of the attachment tip lumen independent of and relative to the distal end portion of the insert.
Consequently, tools exiting or extending from a distal opening in the attachment tip (or from the accessory tubing) do so in a fixed orientation that is substantially aligned with (or angularly fixed relative to) the distal end portion of the insert. The physician is therefore unable to manipulate the attachment tip into position independent of the insert's distal end portion, and one of the few parameters available for positioning the tool may be the depth to which the tool exits and extends beyond the attachment tip, where the tool may droop or drift into the visual field of the endoscope. An alternative parameter is that the tool may be comprised of a memory material or may be carried in a wire member sheath having a natural deflected state and elastic memory to return the wire member sheath (or the tool) to a deflected state. The tool or wire member sheath is coupled to the side of the distal end portion of the insert and, as the tool or sheath is extended beyond a distal tip of the insert, the tool or wire member returns to its elastic memory (i.e., a bended deflected state that curves or defects away from, or toward, the observation field). However, the elastic tool may be difficult for the physician to control in the observation field and working space, and a curved wire member sheath of this type may extend into and obstruct the observation field and working space of the physician's endoscope and/or the visualization of the tool.
In other cases, it is the insert that may articulate. The insert may include articulation control means for manipulating the position of the distal end portion into an articulating (e.g., bending and flexing) position. For those inserts incorporating a working channel built into the endoscope or incorporated into a sheath that fits to or encapsulates the distal end portion of the insert, it is still nevertheless the insert that articulates. The working channel from which a tool exits or extends moves with the movement of the insert and not independently thereof.
For the foregoing reasons, it is desirable to have an endoscopic surgical access device, as taught herein, that gives the physician control over the position and/or orientation of the tool within the visual field of the distal end portion of the insert.